Joyce and Tim started piano lessons at the same time. They both practice about 30 minutes a day and enjoy playing the piano. Despite these similarities, Joyce has mastered many more piano skills than Tim has. Which argument is best supported by these observations?

Joyce and Tim have similar practice routines and both enjoy piano, yet they have made different levels of progress. This suggests that practice and other environmental factors may not explain all differences in piano skill; individual factors, including genetics, may also contribute. The observation does not prove genetics is the cause, but choice A is best supported.

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